Field of the Disclosure
The present disclosure relates to an ink set and a thermal transfer recording sheet.
Description of the Related Art
In recent years, a demand for color-printing in a simple manner photographs/documents taken/created by devices has rapidly further increased with the widespread use of portable color display devices. In particular, in image forming methods employing a thermal transfer technique, the clearness and the color reproduction properties of images are excellent because a dye is used as a coloring agent, a dry process not involving wastewater problems is employed, and the like. Therefore, the demand for the image forming methods has expanded.
As one of the image forming methods employing a thermal transfer technique, a fabric printing method employing a fabric of polyester or the like as a material to be recorded is known. Japanese Patent Laid-Open No. 2014-80539 reports an example of ink jet transfer printing using an anthraquinone-based compound.
However, when an anthraquinone-based magenta pigment and a cyan pigment have been combined, there has been a problem that the reproduction of a red color gamut with a high color saturation demanded in sportswears and the like and a black color with a high density and a high grade has been difficult to achieve.
On the other hand, as one of the image forming methods employing a thermal transfer technique, a thermal transfer recording system employing a thermal transfer sheet is known. As coloring materials for use in the thermal transfer recording system, examples using a yellow dye, a magenta dye, and a cyan dye have been reported (Japanese Patent Laid-Open Nos. 05-262056, 07-096675, and 08-011450). Image formation is performed using ink sheets created using the yellow dye, the magenta dye, and the cyan dye. Therefore, the reproduction of black can be achieved by mixing the three colors (process black). In order to obtain a high grade process black, it is necessary to use a combination of coloring materials having uniform absorption in all the regions of the visible light spectrum. However, when the clearness and the color reproduction properties of an image have been further demanded, a dye with a higher color saturation having a very steep and narrow absorption spectrum has been used, which has posed a problem that wavelength components which cannot be absorbed have remained in color mixing, resulting in the fact that a high grade black has not been able to be formed.